For me, it's entirely circumstantial.
If it's a situation where I feel the minions would look different--either in terms of physical appearance, equipment quality, or what have you--then I'll mention that in the description.
But if it's a situation where I don't think there would be a visible different (if there's no good reason for the minions' equipment to be sub-par, for instance), then no, I don't tell them, and they get to find out in combat.
In no case would I use the terms "minion" or "elite" while giving descriptions.